scholarly journals Domestic Wastewater Treatment: A Comparison between an Integrated Hybrid UASB-IFAS System and a Conventional UASB-AS System

2021 ◽  
Vol 13 (4) ◽  
pp. 1853
Author(s):  
Ayman M. Dohdoh ◽  
Ibrahim Hendy ◽  
Martina Zelenakova ◽  
Ahmed Abdo

The current study presents a detailed evaluation and comparison between two integrated anaerobic–aerobic systems for biological wastewater treatment under equal conditions in all aspects (wastewater characteristics, climatic conditions, reactor sizing, and even the measurement methods). The two examined systems are (i) a hybrid upflow anaerobic sludge blanket (hybrid UASB) coupled with integrated fixed-film activated sludge (IFAS) and (ii) a conventional UASB coupled with activated sludge (AS). The present comparative study aims to evaluate and assess the effect of adding carrier-filling media on the performance of the classical integrated UASB-AS. The two parallel pilot-scale systems, hybrid UASB-IFAS and UASB-AS, were installed and operated at a wastewater treatment plant. Three sets of experiments were conducted to examine the influence of the hydraulic retention time (HRT) on the consequent organic and hydraulic loads, temperature, and recirculation rate of the proposed systems. The main results showed that the two investigated systems had a comparably high efficiency for the removal of organic matters and ammonia. Moreover, a paired sample t-test indicated there was a statistically significant effect of the filling media, and the performance of the hybrid UASB-IFAS increased significantly compared with that of the UASB-AS system. An additional benefit of the filling media on the hybrid system was its high stability when changing the organic and hydraulic loads. The optimum HRT was 6 h, with a total chemical oxygen demand (TCOD) percentage removal of approximately 95% in both examined systems. Treatment of sewage under high and low temperatures indicated that increasing the temperature improved the efficiency of the overall process for both systems significantly.

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.


2019 ◽  
Vol 14 (4) ◽  
pp. 908-920 ◽  
Author(s):  
Oliver Saavedra ◽  
Ramiro Escalera ◽  
Gustavo Heredia ◽  
Renato Montoya ◽  
Ivette Echeverría ◽  
...  

Abstract This study aims to determine the seasonal variability in the performance of a medium size population wastewater treatment plant (WWTP) in Bolivia. The semi-arid area where the WWTP is located is characterized as agricultural land, with an annual rainfall of 500 mm and a mean temperature of 17 °C. The WWTP is built up of five modules, each one comprising two treatment trains composed of an upflow anaerobic sludge blanket (UASB) reactor and horizontal gravel filter. The performance of the full process has been determined based on water quantity and quality. Seven monitoring campaigns of chemical and physical wastewater characteristics were performed from March to December 2017. The measured effluent showed average removal efficiencies of 83 ± 8% and 37 ± 60% for total chemical oxygen demand (COD) and total suspended solids (TSS), respectively. The treatment system has proven to be efficient to remove organic matter and TSS, despite the occurrence of high COD and total solids (TS) influent concentrations, the accumulation of solids at all the processes and the variability of flow and temperature inside the UASB reactors. In order to improve further this efficiency, it is recommended to implement a primary sedimentation unit as a pretreatment for the UASB system that would help to homogenize both the flow and the quality of the influent.


2015 ◽  
Vol 73 (2) ◽  
pp. 309-316 ◽  
Author(s):  
V. Del Nery ◽  
M. H. Z. Damianovic ◽  
R. B. Moura ◽  
E. Pozzi ◽  
E. C. Pires ◽  
...  

This paper assesses a wastewater treatment plant (WWTP) regarding the technology used, as well as organic matter and nutrient removal efficiencies aiming to optimize the treatment processes involved and wastewater reclamation. The WWTP consists of a dissolved air flotation (DAF) system, an upflow anaerobic sludge blanket (UASB) reactor, an aerated-facultative pond (AFP) and a chemical-DAF system. The removal efficiencies of chemical oxygen demand (COD) (97.9 ± 1.0%), biochemical oxygen demand (BOD) (98.6 ± 1.0%) and oil and grease (O&G) (91.1 ± 5.2%) at the WWTP, the nitrogen concentration of 17 ± 11 mgN-NH3 and phosphorus concentration of 1.34 ± 0.93 mgPO4−3/L in the final effluent indicate that the processes used are suitable to comply with discharge standards in water bodies. Nitrification and denitrification tests conducted using biomass collected at three AFP points indicated that nitrification and denitrification could take place in the pond.


2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Agus Rifai ◽  
Rudi Nugroho

A preliminary assessment of an application of sewerage system with Upflow Anaerobic Sludge Blanket (UASB) and Down flow Hanging Sponge (DHS) technology was conducted inNorth Bogor. The Problem which often emerge in management of domestic wastewater is the limited land area and fund to built and operate a wastewater treatment facility. To overcome such problem, it is needed to develop a cheap wastewater treatment technology with high efficiency, easy to operate and also should be compact. The combination technology of UASB and DHS is proposed as an economic wastewater treatment which  easy to handling. Therefore, to make sure that the technology is feasible or not to be built inNorth Bogor, there is need the preliminary assessment. The assessment was conducted through a survey of technical and social economic aspect. The results show that sewerage system using UASB and DHS technology is feasible. Key word: domestic wastewater, upflow anaerobik sludge blanket, downflow hanging sponge, preliminary assessment.


Author(s):  
Narendra Pal Gole

The implementation of wastewater treatment plants has been a challenge for most countries. Economic resources, political will, institutional strength, and cultural background are important factors that define the trajectory of pollution control in many countries. Technology is sometimes mentioned as one of the reasons hindering further development. Therefore, a key objective of this research is to evaluate the performance of a plant based on the 345 MLD Upflow Anaerobic Sludge Blanket (UASB) technology by analyzing the physical and chemical parameters of the water treated by UASB to evaluate the performance of the plant located. at Bharwara Tech from Gomti Nagar Lucknow. In this study, the performance of the wastewater treatment plant and the UASB reactor was calculated. Wastewater is mixed with domestic wastewater, so the concentration of BOD and COD is relatively low. The amount of biogas produced by the UASB reactor is also less than its design value. All STP inlet and outlet water concentration results are displayed graphically.


2017 ◽  
Vol 76 (8) ◽  
pp. 2003-2014 ◽  
Author(s):  
Pollyane Diniz Saliba ◽  
Marcos von Sperling

The objective of this study was to evaluate the behaviour of a system comprising an upflow anaerobic sludge blanket reactor followed by activated sludge to treat domestic sewage. The Betim Central sewage treatment plant, Brazil, was designed to treat a mean influent flow of 514 L/s. The study consisted of statistical treatment of monitoring data from the treatment plant covering a period of 4 years. This work presents the concentrations and removal efficiencies of the main constituents in each stage of the treatment process, and a mass balance of chemical oxygen demand (COD) and nitrogen. The results highlight the good overall performance of the system, with high mean removal efficiencies: BOD (biochemical oxygen demand) (94%), COD (91%), ammonia (72%) and total suspended solids (92%). As expected, this system was not effective for the removal of nutrients, since it was not designed for this purpose. The removal of Escherichia coli (99.83%) was higher than expected. There was no apparent influence of operational and design parameters on the effluent quality in terms of organic matter removal, with the exceptions of the BOD load upstream of the aeration tank and the sludge age in the unit. Results suggest that this system is well suited for the treatment of domestic sewage.


2008 ◽  
Vol 57 (8) ◽  
pp. 1287-1293 ◽  
Author(s):  
A. Jobbágy ◽  
G. M. Tardy ◽  
Gy. Palkó ◽  
A. Benáková ◽  
O. Krhutková ◽  
...  

The purpose of the experiments was to increase the rate of activated sludge denitrification in the combined biological treatment system of the Southpest Wastewater Treatment Plant in order to gain savings in cost and energy and improve process efficiency. Initial profile measurements revealed excess denitrification capacity of the preclarified wastewater. As a consequence, flow of nitrification filter effluent recirculated to the anoxic activated sludge basins was increased from 23,000 m3 d−1 to 42,288 m3 d−1 at an average preclarified influent flow of 64,843 m3 d−1, Both simulation studies and microbiological investigations suggested that activated sludge nitrification, achieved despite the low SRT (2–3 days), was initiated by the backseeding from the nitrification filters and facilitated by the decreased oxygen demand of the influent organics used for denitrification. With the improved activated sludge denitrification, methanol demand could be decreased to about half of the initial value. With the increased efficiency of the activated sludge pre-denitrification, plant effluent COD levels decreased from 40–70 mg l−1 to < 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter


2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.


2017 ◽  
Vol 28 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Daiane Cristina de Oliveira Garcia ◽  
Liliane Lazzari Albertin ◽  
Tsunao Matsumoto

Purpose The purpose of this paper is to evaluate the efficiency of a duckweed pond in the polishing of a stabilization pond effluent, as well as quantify its biomass production. Once an adequate destination is given to the produced biomass, the wastewater treatment plant can work in a sustainable and integrated way. Design/methodology/approach The duckweed pond consisted of a tank with volume 0.44 m3, operating in continuous flow with an outflow of 0.12 m3/day and hydraulic retention time of 3.8 days. Effluent samples were collected before and after the treatment, with analyzes made: daily-pH, dissolved oxygen and temperature; twice a week – total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD); and weekly – total solids (TS) and Biochemical Oxygen Demand (BOD5). The duckweeds were collected each for seven days for its production quantification. Findings The highest efficiency of TN, TP, COD, BOD5 and TS removal were of 74.67, 66.18, 88.12, 91.14 and 48.9 percent, respectively. The highest biomass production rate was 10.33 g/m2/day in dry mass. Research limitations/implications There was great variation in biomass production, which may be related to the stabilization pond effluent conditions. The evaluation of the effluent composition, which will be treated with duckweeds, is recommended. Practical implications The evaluated treatment system obtained positive results for the reduction in the analyzed variables concentration, being an efficient technology and with operational simplicity for the domestic effluent polishing. Originality/value The motivation of this work was to bring a simple system of treatment and to give value to a domestic wastewater treatment system in a way that, at the same time the effluent polluter level is reduced and it is also possible to produce biomass during the treatment process.


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